Buster Olney has a fun little Mariano Rivera story from former outfielder and current V.P. of baseball operations for Baltimore, Brady Anderson.

Back in the day, the Orioles—specifically Roberto Alomar and Rafael Palmeiro—had a special bat, with a special name, they would use specifically for at-bats against Rivera. Palmeiro and Alomar used the bat because it was smaller and they, like many opponents, had trouble making solid contact with Rivera's cutter. The thought was since it was smaller, the bat helped them get inside the cutter easier and it may have actually worked. For their careers, Alomar and Palmeiro had slash lines of .385/.438/.615 and .333/.471/.556, respectively, against Rivera.

Anderson told Olney that while he generally enjoyed the challenge of trying to get a hit off Rivera—and had fairly decent numbers against Mariano himself with his larger bat—he did try the secret bat once. Rivera promptly broke it.

It was 32 inches in length, which made it easier for the hitters to manipulate in the effort to get inside of Rivera's cutter, and the bat was special enough to Alomar and Palmeiro that they bestowed a nickname upon it: Stumpy.

So Stumpy would stay stored away, like a secret weapon, until Rivera was on the mound. Then Stumpy would emerge.